Long-Term Debt (Details) - Revolving credit facility - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Line of Credit Facility [Line Items]
Interest incurred	$ 1,913	$ 2,295	$ 2,090
Capitalized interest	534	563	935
Interest paid (net of capitalized interest)	$ 1,169	$ 1,314	$ 618
Weighted average interest rate	2.20%	2.20%	3.70%